1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
3 /* This Source Code Form is subject to the terms of the Mozilla Public
4  * License, v. 2.0. If a copy of the MPL was not distributed with this
5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
6 
7 #include "mozilla/ClearOnShutdown.h"
8 
9 namespace mozilla {
10 namespace ClearOnShutdown_Internal {
11 
12 Array<StaticAutoPtr<ShutdownList>,
13       static_cast<size_t>(ShutdownPhase::ShutdownPhase_Length)>
14     sShutdownObservers;
15 ShutdownPhase sCurrentClearOnShutdownPhase = ShutdownPhase::NotInShutdown;
16 
InsertIntoShutdownList(ShutdownObserver * aObserver,ShutdownPhase aPhase)17 void InsertIntoShutdownList(ShutdownObserver* aObserver, ShutdownPhase aPhase) {
18   // Adding a ClearOnShutdown for a "past" phase is an error.
19   if (PastShutdownPhase(aPhase)) {
20     MOZ_ASSERT(false, "ClearOnShutdown for phase that already was cleared");
21     aObserver->Shutdown();
22     delete aObserver;
23     return;
24   }
25 
26   if (!(sShutdownObservers[static_cast<size_t>(aPhase)])) {
27     sShutdownObservers[static_cast<size_t>(aPhase)] = new ShutdownList();
28   }
29   sShutdownObservers[static_cast<size_t>(aPhase)]->insertBack(aObserver);
30 }
31 
32 }  // namespace ClearOnShutdown_Internal
33 
34 // Called when XPCOM is shutting down, after all shutdown notifications have
35 // been sent and after all threads' event loops have been purged.
KillClearOnShutdown(ShutdownPhase aPhase)36 void KillClearOnShutdown(ShutdownPhase aPhase) {
37   using namespace ClearOnShutdown_Internal;
38 
39   MOZ_ASSERT(NS_IsMainThread());
40   // Shutdown only goes one direction...
41   MOZ_ASSERT(!PastShutdownPhase(aPhase));
42 
43   // Set the phase before notifying observers to make sure that they can't run
44   // any code which isn't allowed to run after the start of this phase.
45   sCurrentClearOnShutdownPhase = aPhase;
46 
47   // It's impossible to add an entry for a "past" phase; this is blocked in
48   // ClearOnShutdown, but clear them out anyways in case there are phases
49   // that weren't passed to KillClearOnShutdown.
50   for (size_t phase = static_cast<size_t>(ShutdownPhase::First);
51        phase <= static_cast<size_t>(aPhase); phase++) {
52     if (sShutdownObservers[static_cast<size_t>(phase)]) {
53       while (ShutdownObserver* observer =
54                  sShutdownObservers[static_cast<size_t>(phase)]->popLast()) {
55         observer->Shutdown();
56         delete observer;
57       }
58       sShutdownObservers[static_cast<size_t>(phase)] = nullptr;
59     }
60   }
61 }
62 
63 }  // namespace mozilla
64